Planck-scale sensitivity of CMB polarization data

✍ Scribed by Giulia Gubitosi; Luca Pagano

• Book ID: 103870596
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 245 KB
• Volume: 194
• Category: Article
• ISSN: 0920-5632
• DOI: 10.1016/j.nuclphysbps.2009.07.027

✦ Synopsis

We show that the Cosmic Microwave Background (CMB) polarization data gathered by the BOOMERanG 2003 flight and WMAP provide an opportunity to investigate in-vacuo birefringence, of a type expected in some quantum pictures of space-time, with a sensitivity that extends even beyond the desired Planck-scale energy. In order to render this constraint more transparent we rely on a well studied phenomenological model of quantumgravity-induced birefringence, in which one easily establishes that effects introduced at the Planck scale would amount to values of a dimensionless parameter, denoted by ξ, with respect to the Planck energy which are roughly of order 1. By combining BOOMERanG and WMAP data we estimate ξ -0.097 ± 0.075 at the 68% c.l. Moreover, we forecast on the sensitivity to ξ achievable by future CMB polarization experiments (PLANCK, Spider, EPIC), which, in the absence of systematics, will be at the 1-σ confidence of 8.5 × 10 -4 (PLANCK), 6.1 × 10 -3 (Spider), and 1.0 × 10 -5 (EPIC) respectively. The cosmic variance-limited sensitivity from CMB is 6.1 × 10 -6 .